1. Field of the Invention
The present invention relates to an optical module, in particular, a light-emitting module including a Peltier device therein and having a co-axial type package.
2. Related Prior Art
It is well known that a light-emitting module, which installs a semiconductor laser diode for the light-emitting device therein, contains a thermoelectric device, such as Peltier device, for controlling a temperature of the laser diode (hereinafter denoted by LD). In such optical module, the LD is mounted on the Peltier device, and the Peltier device, supplied by the current, controls the temperature of the LD.
However, the optical module having a package of, so called the CAN type or the co-axial type, has various subjects when installs the Peltier device therein. That is, such package, 1) extremely restricts the device mounting area generally called as a stem, 2) shows an inferior heat dissipation efficiency because paths for heat dissipation is restricted to the stem, and 3) the optical axis of the output light makes a right angle to the device mounting area that restricts the arrangement of the device installing.